Dental handpiece.



B.. M. MAYES.

DENTAL HANDPIEGE.

APPLIOATIOH FILED JLY s, 190s.

91 1,510. Patented Feb. 2, 1909,

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noBERTf'MAaTrN MAYEs, or sAN AN'roNio,` TEXAS.

DENTAL HANDHECE.

specification of Letters Patent.

Patented Feb. 2, 1909.

Y y Application filed :any a; 190s. serial Ne. 441,854.

To all tvhom it may concern: '1

Be it known that I, ROBER" MARTIN 'l MAYns, a citizenV of the United States, re-

siding at San Antonio, in the county of Bexar and vState of Texas, have invented Va new and useful Dental Handpiece, of which the following is a specification.

This invention relates to Vdental engine hand pieces; and has for its objectV to provide a simple, accurate and convenient handpiece for holding `dental tools-for straight line work, and for attaching ,theretoV an angle piece by means of which said tools may be held and rotated at an angle to the hand ieee. f Y p With this and other objectsin view the invention consists of the construction, combination and arrangement of parts vhereinafter described and claimed, and illustrated in the accompanying drawing in which Figure 1 is a side view of the hand piece with a right angle tool holder connected thereto; Fig. 2 a longitudinal sectional view of the same; F ig. 3 a similar sectional view of a portion ofthe hand piece with the right angle holder removed and a tool held thereby for straight work; Figs. 4 and 5 perspective views of detail parts ofthe invention, and Fig. 6 is adetail sectional view of the angle piece. l Y

Similar reference numerals are used for the sameparts in all the figures.

In the drawing, 1 represents the casing or barrel of the hand piece` Vhaving a slight conical taper, exteriorly, from its rearend to its tip and, near its rear a circumferential rib or bead 2, preferably'knurled, as shown. The casing 1 is bored longitudinally through its length for a spindle 3, the rear end being counter bored as far as the rib or bead 2 to form a socket, producing thereby a shoulder or seat 4. The tip end is also counter bored for a short distance and threaded throughout its length; the socket `is threaded interiorly for a short distance only. Y Y

Rotatably mounted inthe bore of the casing-l is the spindle 3 havinga collar 5 near its rear end which abuts, against the shoulder 4, and is prevented thereby from moving in a forward direction. The collar 5 is held against the shoulder, and a bearing provided for the rearend of the spindle 3 by a coupling 6 exteriorly threaded on one end 7 to screw into thethreaded socket in the barrel and bear against the rear end of the collar 5.V

The coupling 6 has a `central bore through which the rear end of the spindle 3 extends and in which it has a bearing. The rear lend 9 of the coupling 6 is counter-bored and interiorly threaded for the end of the sheathing 10 which covers the ordinary flexible driving shaft 13 soldered in an axial hole in the rear end 8 of the spindle 3.

The forward end 11 of the spindle 3 is formed into-a tool holder in which may be secured the shank of the bur or drill 25 for straight work or the shaft 14 of an angle piece 12. inwardly from its end 11 a central longitudinal bore 15 is made in the spindle for a sufficient distance and of such diameter as to permit the shaft of an anglepiece, a drill, or other tool to slide freely therein without side play. A transverse slot 18 is cut acrossthe tool holder at the end of the bore 15 from one side thereof inwardly toits center, the bottom of said slot being' fiat and in a plane passing through the axis of said bore. One-half the bore 15 is therefore open to the slot 18 so that when a drill or other tool or a shaft with its end flattened is inserted in the bore with its flat side bearing on the bottom ofthe slot, the rotationof the spindle will necessarily cause the tool to krotate with it.

When the angle piece 12 is to be attached to the hand piece a nozzle 19 having a threaded stud 20 is screwed into the forward end of the casing 1, said stud 20 being bored out to form a socket 2l for the forward end of the spindle 3. The nozzle 19 is reduced or coned towards the angle piece and is provided with an outwardly projecting stem 22 threaded for about one-half its length, the outer end being smooth. On this stem 22 the angle piece 12 is screwed as shown in Fig. 1. A bore of suitable size is formed in the nozzle in which the shaft 14 of the angle piece is mounted. For straight work, the nozzle 19 is removed, and a cap piece 23 substituted therefor, the stem 24 of which is not threaded. A tool 25 with its shank end 26 flattened and slightly bent or curved towards the flattened side is placed in the bore spindle 3 so that its attened side will engage the bottom of the slot 18. The end of the Vtool shank being bent towards the flattened side will strike the inclined end 27 of` and prevent it Vfrom being withdrawn without exercising more force than would be encountered in the Work it has to do.

The angle piece is attached by iirst Withdrawing the tool and unscrewing the cap piece 23, then the angle piece 12 with the coupling 23 screwed thereto and the shaft let projecting beyond the coupling is screwed in position on the hand piece by irst inserting the end ot' the shaft into the spindle 5 until its flattened inclined end engages the bottom of the slot 18.

rhe operation oit the instrument is apparent from the above description. End- Wise movement oi tne spindle is preventedv by the collar 5 thereo liiearing against the shoulder l and the end 7 of the coupling 6.

What is claimed is 1 l. ln a dental hand-piece, the combination With an outer easing, ot a rotatable spindle mounted in the casing and having a central longitudinal bore in its forward end, a transverse slot extending from its periphery to its axis at the base of said bore and having a tlat bottom and an inclined surface extending from the bottom of the bore to the bottom of the slot.

2. in a dental hand-piece, the combination With an outer casing, or" a spindle mounted to rotate axially in said casing and having a central longitudinal bore in its ton Ward end7 a transverse slot extending from its periphery to its axis at the base of said bore and having a fiat bottom and an inclined sui-:tace extending from the bottom of the bore to the bottoni of the slot and adapted to receive a tool-shank having a attened side on its rear end, said rear end being deected slightly towards said {iattened side.

8. in a dental handpiecc, the combination With an outer easing having a central longitudinal bore counter bored at each end, a rotatable spindle iitting said bore and having a collar fitting the rear counter bore, means for retaining said collar and spindle in place,- said spindle. provided with a toolholder on its torivard end comprising a longitudinal bore Jfor tool, and a transverse slot intersecting said bore in a plane passing through its axis to term a plane snr- :laee for a tool to bear on and to be rotated with the spindle. of a nozzle having a spindle bearing Within the easing, a projection in line therewith on its outer end, and a bore extending through the nozzle in line with the bore in the spindle.

il. ln a dental hand-piece7 the combination Wit-h a easing, a spindle rotatably mounted in the easing and having a toolholder on its lorivard end, ot a nozzle hav ing a threaded extension adapted to screw into the forward end of the easing and provided with a ,earing seat on its inner side for the, end of said spindle and a partly threaded stein projecting forwardly `troni the center of said nozzlev on which an angle piece is adapted to screw, l `Cid nozzle having` a central bore in line with said tool-holder to receive the driving shalt ot said anglepiece as it is pushed into the tool-holder.

In testimony that l elaini the lioregoing as my own7 have hereto aliixed my signature in the presence ot tivo Witnesses.

ROBERT lxliR'lN MYES.

T. H. Bass, Gaiarin A. Ross. 

